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Topics - lloydsp

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1
Members Projects / Auto-tracing a captured image
« on: January 03, 2025, 01:26:37 am »
This latest X-Acto blade holder project made me realize that I have no good way to capture the outline of a complex shape, and translate that into a CamBam drawing.

Do any of you have any favorite methods, like an auto-tracing algorithm, that would do that?

Lloyd

2
Members Projects / A really 'fun', tiny pocket
« on: December 31, 2024, 21:17:46 pm »
I'm making a precision blade-holder on a client's project for an X-Acto #11 blade, and need to mill a pocket in 6061 about 0.020" deep that retains the 'locater stud' all X-Acto blades have.  As such, the only endmill cutter I have that will fit between the stud and the edge of the blade is only 0.0625" in diameter.  And yes, it's an actual end mill, not a router bit.  They recommend 12K rpm and no deeper than 0.030" per pass at 10 ipm with flood for 6061.

That wouldn't be a problem at 12K rpm, but my mill won't go faster than 4200 rpm.  So BOY, and I going to have to cut gently and slowly!

I'm too tired this afternoon to be as attentive as I must be, so it'll wait until the New Year!

Happy New Year, ALL!

Lloyd

3
Members Projects / "Pick and hold" circuit
« on: June 10, 2024, 17:44:58 pm »
Modern small form-factor solenoid air valves (even name brands) seem not to be designed for better than 50% duty cycles.  They all tend to overheat, if held 'actuated' for longer than eight or ten minutes.  It's worse if ventilation is limited or ambient temperatures are high (say, "Florida").

Because the vendors cannot predict what will be the 'quiescent' state of a machine vs. the 'off' state, this just isn't right.  The coils won't last at elevated temperatures.  But there's a way to solve it simply.

It's called a 'pick and hold' circuit.  Basically, it's just an RC network that charges a capacitor large enough to 'pick' the solenoid, but then limits the applied voltage to a 'hold voltage' of (say) half of the solenoid's pick voltage rating.  All it requires is a careful selection of the limiting resistor's value and dissipation rating and the capacitor value, and a slow-enough cycle time so that the cap' has a chance to recharge between 'picks'.

For the ones I'm employing, their coil resistance is about 50 ohms, so a 56 ohm, 2-watt limit resistor with a 1000uf cap works fine.

I could do it with PWM with SSRs, but in this machine the solenoids were controlled by mechanical relays, and PWM'ing them would wear the relays out in a day or two, so the RC networks are the solution.  Simple stuff -- but you wish you didn't have to do it!

L

4
When might we expect it to be renewed?
L
(Last post, until I see it renewed).

5
Members Machines / Hooray! Much-needed accessory in my shop!
« on: January 30, 2024, 21:13:29 pm »
I just wired and got working a new POE PTZ camera for my router bay.

The router bay is far enough from my office that I cannot clearly hear whether or not a machine is still cutting over the noise the vacuum blower and two large dust collectors make.  So, I decided to add a camera so I could monitor them visually from my office.

I ordered a camera from Hugolog.  AVOID this product!  It will ONLY work on a smart-phone, and has no working provisions for viewing on any PC.  They claim to have software to do it, but 1) it doesn't work, even on the versions of browsers and operating systems they claim, and 2) they want all sorts of personal and hazardous information like your personal passwords to your network and PC in order to enable it (I set up dummies for the tests).  I ended up sending the camera back for a refund.  It just won't work on anything but my phone.

Then I ordered an outdoor WIRED POE camera from Techage.  It worked perfectly on the first try.  It has automatic dim/night illumination, and PTZ controls from my web browser.

Now, I can monitor my machines in a little window on my PC desktop while I work!  Yippee!

Lloyd

6
CamBam help (General usage) / May 2024 be a year of renewal and reward!
« on: January 01, 2024, 18:44:44 pm »
Happy New Year to all my friends here.  I wish you all the best of fortunes in this year of renewal.

Lloyd

7
Members Machines / Please be more careful than I was!
« on: October 05, 2023, 18:02:33 pm »
This Tuesday, about 11am EST US, I 3/4 amputated the distal 5/8" of my left thumb by slipping on a table saw!  Owee!

It sawed completely through the bone.  The hand surgeon said that was actually a good thing.  Had it shattered, it would have required surgery.  As it is, it MAY heal.  Sensation will probably not return.  They really don't know the outcome, yet.  That tip may have to come off.  It just depends upon whether or not the severed portion re-vascularizes.  (irk!) So far, it looks 'favorable'.

Be careful, guys!

Lloyd

8
CamBam Shop Feedback / End of the line?
« on: August 08, 2023, 21:08:18 pm »
I'm sort of 'guessing' this last three weeks is an indication we won't have this forum for much longer.  I hope Andy preserves the content in some sort of archival form, and that he preserves all the files folks have worked on over the years.

Lloyd

9
Members Projects / Torque-limiting fixture clamping
« on: June 14, 2023, 15:40:14 pm »
I just received an email from Fixtureworks.com describing a product they carry that may be useful to some here.  It's 'Torque-limiting fixture clamps'.  They're available in 2Nm and 3Nm torque ranges, and they are user-adjustable for torque.

In use, they 'click' when the desired torque is reached.  I'm in the middle of a client project right now where these might be useful.

Lloyd

10
CamBam help (General usage) / Security Certificate has expired
« on: March 19, 2023, 11:18:21 am »
The site is essentially unusable in its current state.  One gets a 'security challenge' after every action.
LS

11
Today, I set-to cleaning a little Ingersol Rand air-piloted shuttle valve used to control a small 1/2-ton pneumatic press.  I've cleaned and repaired these things dozens of times.

But this time, I was greeted by GLOBS of black goo, as thick as HOT road tar, and blacker than anything I've ever seen -- WAY blacker than tar.  It was blacker than the darkest printer's ink!  And, I couldn't get it off of anything.

I tried mineral spirits, gasoline, acetone, and even plain engine oil.  NOTHING touched it.  I was covered with the stuff.  It stains everything.  I couldn't get it off the part or off of me.  So, in a panic, I grabbed a squirt of GoJo hand cleaner.

That didn't get me exactly clean but it did tend to get most of the gunk off.  So... a clue.  I broke out a bottle of detergent spray surface cleaner.  That did an even better job, but still not 'clean'.  Then, some straight Greased Lightning, no dilution.

It cleaned everything nicely, except under my fingernails, and got all the smutch off the part, as well.  So, now...

What the HECK is that goo?  Have you ever seen it, dealt with it, identified it?  A clue is that the O-rings on the valve's shuttle are NOT deteriorated.  The shuttle was just stuck in this gunk.

Help me solve this puzzle, please.  A clue is that Greased Lightning's main cleaning ingredient is plain-old LYE (sodium hydroxide).  That would tend to indicate that the goo is of animal or vegetable origin, but I'm unaware of any such 'greases' that are completely insoluble in petroleum solvents.

Lloyd

12
Members Projects / Is it courage or stupidity?
« on: December 05, 2022, 19:53:16 pm »
I _think_ it takes a bit of courage to start ramming a 20mm drill 54mm deep into a $254 USD block of aluminum!  You always wonder -- "Did I get everything right?"

I mitigate the fear by jacking up the spindle and doing a partial test pass, just to watch what it will do.  But still -- SCARY!

(Presently mill-drilling 156 7/8" holes 2" deep into an expensive block of stock!)

Lloyd

13
Members Machines / Manual spindle speed control?
« on: December 03, 2022, 20:45:01 pm »
I've always, only, used automatic speed control on my mill's spindle.  But I've had a failure that allows me to control the speed manually, but will not allow automatic control.

How do I change my post-processor or the g-code in a way that will allow me to start and set my spindle speed manually, any time a speed change is requested in the g-code?

I've never done it.

Thanks,
Lloyd

14
Members Machines / Ooof! R2E4 speed control failed!
« on: December 03, 2022, 01:26:36 am »
During a job today, my Centroid-converted R2E4 Bridgeport apparently broke a gear, a shaft, or (hopefully) a shear pin in the speed control assembly.  The air motor that moves the speed control chain runs, but the chain doesn't move.

I haven't yet finished disassembling the top end of the machine to inspect the shaft and gears.  In the meanwhile, the machine will run at a paltry 1000 rpm, but no more.  It's hard to do any serious work at that sort of spindle speed.  You can adjust feeds to match, but BOY would it be slow boring 140 5/8" holes 2" deep!

Anyway... tomorrow is a Saturday, so I'm going to take the day off from machining, and troubleshoot.  Pray for me that it's just a busted shear pin between the motor shaft and helical gear!  Anything more, and I'll have to figure out how to adjust the speed manually, because parts for that assembly are about two weeks out -- and I have to finish this job ASAP.

Lloyd

15
CamBam Shop Feedback / Hurricane predicted to hit here!
« on: September 23, 2022, 16:57:43 pm »
I'll be spending the next day or two putting-up protective coverings on all our windows.  The skylights are done!

I'll still be checking posts and emails, but less-frequently, until I get the house and property secured for the storm.

It's supposed to hit Tampa as a Category-3 storm, and still be at least a Cat-1 when it crosses the state and gets here.

Wish us luck!

Lloyd

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